Carrier 48FC M20 Series Service And Maintenance Instructions page 120

PRESSURES
Gas Inlet Pressure
Gas Manifold Pressure
Refrigerant Suction
Refrigerant Discharge
Verify Refrigerant Charge using Charging Charts
GENERAL
Economizer minimum vent and changeover settings to job requirements (if equipped)
Verify smoke detector unit shutdown by utilizing magnet test
Verify outdoor fan operation. On units with head pressure controls, verify outdoor fan ramps up
IV. HUMIDI-MIZER ® SYSTEM START-UP
STEPS
1. Start unit In cooling (Close Y1)
OBSERVE AND RECORD
A. Suction pressure
B. Discharge pressure
C. Entering air temperature
D. Leaving air temperature
2. Switch unit to mixed cool and reheat mode (subcool)
OBSERVE
A. Reduction in suction pressure (5-7 psi expected)
B. Discharge pressure unchanged
C. Delta temperature decreases, close to neutral air
3. Switch unit to hot gas reheat mode.
OBSERVE
A. Suction pressure increases to normal cooling level
B. Discharge pressure decreases (35-50 psi) (Limited by head pressure control)
C. Liquid temperature returns to normal cooling level
4. With unit in dehumid mode switch to heating and verify compressor and outdoor fan stop
5. Turn off heating, cooling, and reheat, restore set points for thermostat and humidistat
© 2024 Carrier
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480333-01
STAGE 1
STAGE 2
Printed in U.S.A. Form 48FC-20-30-01SM
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_______________ PSIG
_______________ PSIG
_______________ ° F
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Pg CL-2 1-24 Replaces: NEW